What led to the formation of the Progressive party in U.S. politics?

The Progressive Party, also called the BULL MOOSE PARTY, was  a political party that was formed at 1912 during its presidential elections, where Theodore Roosevelt lost the Republican votes to William Tart, his once hand-picked successor for presidency, after stepping down as President of USA. Feeling that the President now was weak and incapable of handling his task, Roosevelt challenged his position and his bid for re-election of Presidency for a second term. This cause a major divide between the Republican party, causing Roosevelt to pull his delegates out of the convention and forming a new party, the Progressive Party. His main policy and motive for this new party was to "dissolve the unholy alliance between corrupt businesses and politics". This gave Woodrow Wilson, another political candidate for the Democrats to use the opportunity to garner support and votes for his philosophy of "New Freedom", and allowed him to become President of USA in 1912.

Later on, the Progressive Part did terribly at the 1914 Elections and soon faded into oblivion. Roosevelt soon returned to the Republican Party.